The invention is related to a rolling element bearing which operates under starved lubrication conditions. In such cases, not enough lubricant is available in the inlet side of the contact for entrainment such that a lubricant film of sufficient thickness in the contact areas defined by the contacts between the rolling elements and the rings is formed. In normal operating conditions the film thickness between rings and rolling elements is determined by the geometry of the contacts, the lubricant properties, such as viscosity, and the entraining velocity. In starved lubrication conditions, the quantity of lubricant also plays a role.
In that case the lubricant film thickness in the contact areas may become so small that the surfaces, or surface asperities, of the rolling elements and the rings will touch. As a consequence, the life of the bearing is reduced by adhesive wear or surface distress.
The reduction of film thickness can also lead to a reduction of life caused by contamination. Larger particles can no longer freely pass the contact but will cause dents which may reduce bearing life again.